Reproducing apparatus, display apparatus, reproducing method, and display method

ABSTRACT

A transport signal transmitted from a television receiver apparatus  720  through a signal line  708  is subjected to a separation operation by a transport-signal processor  713  and decoded by a video-signal decoding unit  714  and an audio-signal decoding unit  715 . A decoded video signal is supplied through a signal line  701  to the television receiver apparatus  720 . Video processing time of the television receiver apparatus  720  is obtained by a delay-information obtaining unit  716  through a signal line  703 . An audio-signal delaying unit  717  delays an audio signal decoded by the audio-signal decoding unit  715  in accordance with the video processing time obtained by the delay-information obtaining unit  716  and outputs the audio signal to a speaker  750.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application is a national phase entry under 35 U.S.C. §371of International Application No. PCT/JP2008/070863 filed Nov. 17, 2008,published on May 28, 2009 as WO 2009/066634 A1, which claims priorityfrom Japanese Patent Application No. JP 2007-303186 filed in theJapanese Patent Office on Nov. 22, 2007.

TECHNICAL FIELD

The present invention relates to reproducing apparatuses and displayapparatuses, and particularly relates to a reproducing apparatus and adisplay apparatus which reproduce and display digital signals, such asaudio signals and video signals, and processing methods thereof.

BACKGROUND OF THE INVENTION

In recent years, as AV (Audio/Visual) apparatuses using digital signals,such as audio signals and video signals, have been broadly used, variousmethods have been proposed as interfaces for transmitting digitalsignals among the AV apparatuses. As such an interface, an IEEE(Institute of Electrical and Electronics Engineers) 1394 standard and anHDMI (High-Definition Multimedia Interface) standard (HDMI is aregistered trademark), for example, are generally known (refer to PatentDocument 1, for example.)

When AV apparatuses are connected to each other using such an interface,it is assumed that video images are displayed using a televisionreceiver apparatus and sound is output from an AV amplifier. In thiscase, since video processing time of the television receiver apparatusand audio processing time of the AV amplifier are different from eachother, there arises a problem in that time lag occurs between a videoimage and sound. To address this problem, a system, for example, whichattains synchronization (lip sync) between a reproduced video image andreproduced sound by supplying processing time for video-image processingin accordance with the HDMI standard from the television receiverapparatus to the AV amplifier so that processing of audio signals isdelayed has been proposed (refer to Patent Document 2, for example).

Patent Document 1: Japanese Unexamined Patent Application PublicationNo. 2007-267116 (FIG. 1)

Patent Document 2: Japanese Unexamined Patent Application PublicationNo. 2006-033436 (FIG. 1)

SUMMARY OF THE INVENTION

When AV apparatuses are connected to each other in accordance with theHDMI standard, video signals and audio signals are transmitted by meansof a serial transmission method referred to as TMDS (TransitionMinimized Differential Signaling). In this TMDS, the transmissiondirection is one way so that high-speed transmission is performed.Therefore, depending on a connection state of the apparatuses, sound maynot be output from an apparatus desired by a user. Furthermore, someapparatuses may not independently decode digital signals by themselves,and in this case, the decoding processing should be entrusted to anotherapparatus. In this case also, the lip sync described above should betaken into consideration.

The present invention has been made in view of such situations, and anobject of the present invention is to flexibly perform decodingprocessing on video signals and audio signals in a system employing aninterface based on one-way transmission, such as the HDMI standard.

The present invention has been made to solve the above problem, and afirst aspect of the present invention is to provide a reproducingapparatus and a reproducing method thereof, the reproducing apparatusbeing characterized by including separation means for receiving a streamsignal including an encoded video signal and an encoded audio signalfrom a stream generation apparatus and separates the encoded videosignal and the encoded audio signal from the stream signal, video-signaldecoding means for decoding the encoded video signal and outputting thedecoded video signal to a video-image outputting apparatus, audio-signaldecoding means for decoding the encoded audio signal so as to generatean audio signal, and audio-signal processing means for obtaining aperiod of time required for processing the video signal in thevideo-image outputting apparatus as video processing time, delaying theaudio signal in accordance with the video processing time, andthereafter supplying the delayed audio signal to an audio outputtingapparatus. By this, an operation of delaying the audio signal includedin the stream signal received from the stream generation apparatus inaccordance with the period of time required for processing the videosignal in the video-image outputting apparatus is realized.

In the first aspect, the audio-signal processing means may obtain thevideo processing time through a control signal line connected betweenthe audio-signal processing means and the video-image outputtingapparatus. The control signal line may be realized by a display datachannel (DDC) included in an HDMI cable.

Furthermore, in the first aspect, the separation means may receive thestream signal through a data signal line connected between theseparation means and the stream generation apparatus. In this case,assuming that the stream generation apparatus is included in thevideo-image outputting apparatus, the audio-signal processing means mayobtain the video processing time through the data signal line. Moreover,in this case, the data signal line may correspond to a reserved line anda hot-plug detection line included in an HDMI cable.

Furthermore, in the first aspect, the audio-signal decoding means mayoutput the decoded audio signal to the video-image outputting apparatus,and the audio-signal processing means may measure a temporal differencebetween an audio signal returned from the video-image outputtingapparatus and the audio signal decoded by the audio-signal decodingmeans as the video processing time. By this, an operation of delayingthe decoded audio signal in accordance with a temporal differencebetween an audio signal returned from the video-image outputtingapparatus and the decoded audio signal is realized. In this case, thereproducing apparatus may further include first reception means forextracting the stream signal from a difference signal received through adata signal line connected between the first reception means and thevideo-image outputting apparatus, and second reception means forextracting the returned audio signal from an in-phase signal receivedthrough the data signal line. By this, an operation of transmitting thestream signal and the audio signal through the same data signal line isrealized. Moreover, in this case, the data signal line may be realizedby a reserved line and a hot-plug detection line included in an HDMIcable.

A second aspect of the present invention is to provide a displayapparatus and a display method thereof, the display apparatus is beingcharacterized by including: stream-signal generation means forgenerating a stream signal including an encoded video signal and anencoded audio signal, connection-information management means formanaging connection information regarding a state of connection toanother apparatus, stream-signal switching means for determining whethera decoding apparatus which decodes the stream signal has been connectedin accordance with the connection information, and performing switchingso that the decoding apparatus outputs the stream signal when thedecoding apparatus is connected, display control means for receiving avideo signal decoded by the decoding apparatus and displaying the videosignal in display means, and video-processing-time supplying means forsupplying a period of time required for processing the video signalperformed by the display control means to the decoding apparatus asvideo processing time. By this, an operation of transmitting a requestfor decoding processing to another decoding apparatus in accordance witha state of connection to another apparatus is realized.

Furthermore, in the second aspect, the display apparatus may furtherinclude separation means for separating the encoded video signal and theencoded audio signal from the stream signal, and video-signal decodingmeans for decoding the encoded video signal so as to generate a videosignal. The stream-signal switching means may perform switching so thatthe stream signal is output to the separation means when the decodingapparatus is not connected, and the display control means may display avideo signal decoded by the decoding apparatus in the display means whenthe decoded apparatus is connected whereas the display control means maydisplay the video signal decoded by the video-signal decoding means inthe display means when the decoding apparatus is not connected. By this,an operation of selecting the video-signal decoding means or anotherdecoding apparatus to decode the encoded video signal is realized.

Moreover, in the second aspect, the display apparatus may furtherinclude n video-signal decoding means (n is an integer equal to orlarger than 0) for decoding the encoded video signal. By this, anoperation of displaying video images corresponding to the number ofvideo signals larger than the number of the video-signal decoding meansis realized.

Furthermore, in the second aspect, the video-processing-time supplyingmeans may supply the video processing time through a control signal lineconnected between the video-processing time supplying means and thedecoding apparatus. In this case, the control signal line may berealized by a display data channel (DDC) included in an HDMI cable.

Moreover, in the second aspect, the display apparatus further includesaudio-signal returning means for receiving an audio signal decoded bythe decoding apparatus and returning, at a timing when a video signaldecoded by the decoding apparatus is displayed in the display means, theaudio signal corresponding to the video signal to the decodingapparatus. By this, an operation of measuring a period of time requiredfor processing the video signal in the display apparatus by the decodingapparatus is realized. In this case, the display apparatus may furtherincludes first transmission means for transmitting the stream signalthrough a data signal line connected between the first transmissionmeans and the decoding apparatus as a differential signal, and secondtransmission means for superimposing an audio signal returned by theaudio-signal returning means on the data signal line as an in-phasesignal and transmitting the superimposed audio signal to the decodingapparatus. By this, an operation of transmitting the stream signal andthe audio signal through the same data signal line is realized. In thiscase, the data signal line may be realized by a reserved line and ahot-plug detection line included in an HDMI cable.

According to the present invention, an advantage in which decodingprocessing is flexibly performed on a video signal and an audio signalin a system using an interface based on a single-direction transmission,such as an HDMI standard, is obtained.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram schematically illustrating a configuration of aninterface complying with an HDMI standard.

FIG. 2 is a diagram illustrating an example of arrangement of pins of aconnector complying with the HDMI standard.

FIG. 3 is a diagram illustrating examples of internal configurations ofa source apparatus 100 and a sync apparatus 200 according to anembodiment of the present invention.

FIG. 4 show diagrams illustrating examples of configurations of asource-side transmission/reception circuit 140 and a sync-sidetransmission/reception circuit 250 according to the embodiment of thepresent invention.

FIG. 5 show diagrams illustrating examples of configurations of async-apparatus-type detection circuit 110 and a source-apparatus-typedetection circuit 210 according to the embodiment of the presentinvention.

FIG. 6 show diagrams illustrating examples of configurations of aplug-connection detection circuit 120 and a plug-connection transmissioncircuit 220 according to the embodiment of the present invention.

FIG. 7 is a diagram illustrating an example of a configuration of areproducing apparatus 710 according to the embodiment of the presentinvention.

FIG. 8 is a diagram illustrating an example of a configuration of atelevision receiver apparatus 720 according to the embodiment of thepresent invention.

FIG. 9 is a diagram illustrating an example of a data configurationstored in a delay information storage unit 721 according to theembodiment of the present invention.

FIG. 10 is a diagram illustrating an example of a procedure ofprocessing of the reproducing apparatus 710 according to the embodimentof the present invention.

FIG. 11 is a diagram illustrating an example of a procedure ofprocessing of the television receiver apparatus 720 according to theembodiment of the present invention.

FIG. 12 is a diagram illustrating an example of another systemconfiguration according to the embodiment of the present invention.

FIG. 13 is a diagram illustrating a path of an audio signal in theexample of the other system configuration according to the embodiment ofthe present invention.

FIG. 14 is a diagram illustrating an example of a screen displayaccording to the embodiment of the present invention.

FIG. 15 is a diagram illustrating examples of modifications of internalconfigurations of the source apparatus 100 and the sync apparatus 200.

FIG. 16 show diagrams illustrating examples of modifications ofconfigurations of the source-side transmission/reception circuit 140 andthe sync-side transmission/reception circuit 250 according to theembodiment of the present invention.

FIG. 17 is a diagram illustrating an example of a modification of thereproducing apparatus 710 according to the embodiment of the presentinvention.

FIG. 18 is a diagram illustrating an example of a modification of aconfiguration of the television receiver apparatus 720 according to theembodiment of the present invention.

FIG. 19 is a diagram illustrating an example of a modification of theprocedure of the processing of the reproducing apparatus 710 accordingto the embodiment of the present invention,

FIG. 20 is a diagram illustrating an example of a modification of theprocedure of the processing of the television receiver apparatus 720according to the embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of the present invention will now be described withreference to the accompanying drawings. Here, assuming that an interfacecomplying with an HDMI standard is employed, a system in which a requestof decoding processing is transmitted between apparatuses connected witheach other through the interface will be described.

FIG. 1 is a diagram schematically illustrating a configuration of aninterface complying with an HDMI standard. In the HDMI standard, atransmission direction of a basic high-speed transmission line isdetermined to be a single direction, and a transmission-side apparatusis referred to as a source apparatus and a reception-side apparatus isreferred to as a sync apparatus. In this example, a source apparatus 100and a sync apparatus 200 are connected to each other through an HDMIcable 300. Furthermore, the source apparatus 100 includes a transmitter101 which performs a transmitting operation, and the sync apparatus 200includes a receiver 201 which perform a receiving operation.

For the transmission between the transmitter 101 and the receiver 201, aTMDS serial transmission method is employed. In the HDMI standard, videosignals and audio signals are transmitted using three TMDS channels 310to 330. That is, in an effective image period which is defied as aperiod excepting a horizontal blanking period and a vertical blankingperiod from a period from when a certain vertical synchronization signalis supplied to when the next vertical synchronization signal issupplied, a differential signal corresponding to pixel data of an imagefor one screen which has not been compressed is transmitted in a singledirection to the sync apparatus 200 through the TMDS channels 310 to330. Furthermore, in the horizontal blanking period or the verticalblanking period, a differential signal corresponding to audio data,control data, or other auxiliary data is transmitted in a singledirection to the sync apparatus 200 through the TMDS channels 310 to330.

In the HDMI standard, a clock signal is transmitted through a TMDS clockchannel 340. Each of the TMDS channels 310 to 330 transmits image dataof 10 bits in one clock in which the TMDS clock channel 340 performstransmission.

DETAILED DESCRIPTION

Furthermore, in the HDMI standard, a display data channel (DDC) 350 isprovided. The display data channel 350 is used when a source apparatusreads E-EDID (Enhanced Extended Display Identification Data) informationof the sync apparatus 200. The E-EDID information corresponds to, whenthe sync apparatus 200 is a display apparatus, information on settingincluding a type of the apparatus, resolution, a color characteristic,and timing, and performance. The E-EDID information is stored in an EDIDROM 202. Note that, although not shown, as with the sync apparatus 200,the source apparatus 100 may store the E-EDID information and transmitsthe E-EDID information to the sync apparatus 200 as needed.

Moreover, in the HDMI standard, a CEC (Consumer Electronics Control)line 361, a reserved line 362, and a HPD (Hot Plug Detect) line 363, forexample, are provided. The CEC line 361 is a line used forbi-directional communication of apparatus-control signals. The displaydata channel 350 is used for one-to-one connection between apparatuseswhereas the CEC line 361 is used for direct connection to allapparatuses connected to the HDMI.

The reserved line 362 is a line which is not used in the HDMI standard.The HPD line 363 is a line used to detect connection (Hot Plug) toanother apparatus through a cable complying with the HDMI. In thisembodiment of the present invention, it is assumed that Ethernet(registered trademark) signals are transmitted using the reserved line362 and the HPD line 363.

FIG. 2 is a diagram illustrating an example of arrangement of pins of aconnector complying with the HDMI standard. Here, the relationshipbetween a pin number 301 and a signal name 302 in a pin arrangementreferred to as a type A is shown.

Each of the TMDS channels 310 to 330 and the TMDS clock channel 340includes three pins for a positive electrode, a shield, and a negativeelectrode. The first to third pins correspond to the TMDS channel 330,the fourth to sixth pins correspond to the TMDS channel 320, the seventhto ninth pins correspond to the TMDS channel 310, and the 10th to 12thcorrespond to the TMDS clock channel 340.

Furthermore, the 13th pin, the 14th pin, and the 19th pin correspond tothe CEC line 361, the reserved line 362, and the HPD line 363,respectively. Moreover, the display data channel 350 includes three pinsfor a serial clock (SCL), serial data (SDA), and the ground whichcorrespond to the 15th to 17th pins, respectively. Note that, the ground(the 17th pin) of the display data channel 350 is shared by the groundof the CEC line 361. The 18th pin corresponds to a power supply line (+5V).

FIG. 3 is a diagram illustrating examples of internal configurations ofthe source apparatus 100 and the sync apparatus 200 according to theembodiment of the present invention. Here, configurations regarding thereserved line 362 and the HPD line 363 are shown. The source apparatus100 includes a sync-apparatus-type detection circuit 110, aplug-connection detection circuit 120, a source-sidetransmission/reception circuit 140, and an Ethernet (registeredtrademark) transmission/reception circuit 160. Furthermore, the syncapparatus 200 includes a source-apparatus-type detection circuit 210, aplug-connection transmission circuit 220, a sync-sidetransmission/reception circuit 250, and an Ethernet (registeredtrademark) transmission/reception circuit 260.

Although the reserved line 362 is not used in the HDMI standard asdescribed above, it is used here to detect a type of an apparatus to beconnected, for effective use of the pins. That is, thesync-apparatus-type detection circuit 110 of the source apparatus 100detects a type of the sync apparatus 200 through the reserved line 362.Furthermore, the source-apparatus-type detection circuit 210 of the syncapparatus 200 detects a type of the source apparatus 100 through thereserved line 362. It is assumed that a type of an apparatus(hereinafter referred to as an HDMI expanded apparatus) which enablesbi-directional transmission of Ethernet (registered trademark) signalsthrough the reserved line 362 and the HPD line 363 in accordance with anexpanded HDMI standard is employed as the types of the apparatuses.

The HPD line 363 is used to detect connection to another apparatus usingthe HDMI cable as described above. The plug-connection transmissioncircuit 220 of the sync apparatus 200 transmits information on aconnection of the sync apparatus 200 by biasing a predetermined voltageto a terminal connected to the HPD line 363. The plug-connectiondetection circuit 120 of the source apparatus 100 detects a connectionof the sync apparatus 200 by comparing a potential of a terminalconnected to the HPD line 363 with a reference potential.

In the embodiment of the present invention, each of the source-sidetransmission/reception circuit 140 and the sync-sidetransmission/reception circuit 250 are connected to the reserved line362 and the HPD line 363 which have functions as described above. Thatis, the source-side transmission/reception circuit 140 of the sourceapparatus 100 is connected to the reserved line 362 and the HPD line 363through capacitors 131 and 132, respectively, and a resistor 133.Furthermore, the sync-side transmission/reception circuit 250 of thesync apparatus 200 is connected to the reserved line 362 and the HPDline 363 through capacitors 231 and 232, respectively, and a resistor233.

The source-side transmission/reception circuit 140 is used to connectEthernet (registered trademark) signals transmitted through the reservedline 362 and the HPD line 363 in a bi-direction manner to the Ethernettransmission/reception circuit 160.

The sync-side transmission/reception circuit 250 is used to connectEthernet (registered trademark) signals transmitted through the reservedline 362 and the HPD line 363 in a bi-direction manner to the Ethernettransmission/reception circuit 260.

The Ethernet (registered trademark) transmission/reception circuits 160and 260 transmit and receive Ethernet (registered trademark) signals,and perform bi-directional communication complying with an internetprotocol (IP), for example. In this case, as an upper layer of theinternet protocol (IP), a TCP (Transmission Control Protocol) and a UDP(User Datagram Protocol) may be used. The Ethernettransmission/reception circuits 160 and 260 are realized by the relatedart.

FIG. 4 is a diagram illustrating examples of configurations of thesource-side transmission/reception circuit 140 and the sync-sidetransmission/reception circuit 250 according to the embodiment of thepresent invention.

As shown in (a) of FIG. 4, the sync-side transmission/reception circuit250 includes amplifiers 510, 520, 530, and 550, an inverter 541, and anadder 542.

The amplifier 510 amplifies signals supplied from the Ethernet(registered trademark) transmission/reception circuit 260 through signallines 511 and 512. Signals supplied from the signal lines 511 and 512are differential signals, and the amplifier 510 operates by differentialinput.

The amplifier 520 amplifies outputs of the amplifier 510. Outputs fromthe amplifier 520 correspond to differential signals, and a positivesignal is supplied to the reserved line 362 and a negative signal issupplied to the HPD line 363.

The amplifier 530 amplifies signals supplied from the reserved line 362and the HPD line 363. The signals supplied from the reserved line 362and the HPD line 363 correspond to differential signals, and theamplifier 530 operates by differential input.

The inverter 541 corresponds to a circuit which inverts an output of theamplifier 510. The adder 542 corresponds to a circuit which adds anoutput of the inverter 541 and an output of the amplifier 530 to eachother. That is, the inverter 541 and the adder 542 are used to supply asignal obtained by removing an output signal of the sync apparatus 200from signals of the HPD line 363 and the reserved line 362 to theamplifier 550.

The amplifier 550 amplifies an output of the adder 542. Outputs of theamplifier 550 are differential signals, and a positive signal issupplied to a signal line 558, and a negative signal is supplied to asignal line 559. The Ethernet (registered trademark)transmission/reception circuit 260 is connected to the signal lines 558and 559, and a signal obtained by removing a signal output from the syncapparatus 200 from signals supplied from the reserved line 362 and theHPD line 363 is supplied to the Ethernet (registered trademark)transmission/reception circuit 260.

As shown in (b) of FIG. 4, the source-side transmission/receptioncircuit 140 includes amplifiers 410, 420, 430, and 450, an inverter 441,and an adder 442. The source-side transmission/reception circuit 140 hasa configuration the same as that of the sync-side transmission/receptioncircuit 250. The amplifiers 410, 420, 430, and 450, the inverter 441,and the adder 442 correspond to the amplifiers 510, 520, 530, and 550,the inverter 541, and the adder 542, respectively. The Ethernet(registered trademark) transmission/reception circuit 160 is connectedto the amplifiers 410 and 450.

FIG. 5 is a diagram illustrating examples of configurations of thesync-apparatus-type detection circuit 110 and the source-apparatus-typedetection circuit 210 according to the embodiment of the presentinvention.

As shown in (a) of FIG. 5, the sync-apparatus-type detection circuit 110includes resistors 111 and 112, a capacitor 113, and a comparator 116.The resistor 111 is used to pull up the reserved line 362 to +5V. Theresistor 111 is included only when the source apparatus 100 is anapparatus of a specific type (for example, an extended HDMI apparatus),and the pull-up operation is not performed when the source apparatus 100is not the apparatus of the specific type. The resistor 112 and thecapacitor 113 constitute a low-pass filter. An output of the low-passfilter is supplied to a signal line 114. The comparator 116 compares aDC potential supplied from the low-pass filter to the signal line 114with a reference potential applied to a signal line 115.

As shown in (b) of FIG. 5, the source-apparatus-type detection circuit210 includes resistors 211 and 212, a capacitor 213, and a comparator216. The resistor 211 is used to pull down the reserved line 362 to theground potential. The resistor 211 is included only when the syncapparatus 200 is an apparatus of the specific type, and the pull-downoperation is not performed when the sync apparatus 200 is not theapparatus of the specific type. The resistor 212 and the capacitor 213constitute a low-pass filter. An output of the low-pass filter issupplied to a signal line 215. The comparator 216 compares a DCpotential supplied from the low-pass filter to the signal line 215 witha reference potential applied to a signal line 214.

When the sync apparatus 200 is the apparatus of the specific type, theresistor 211 performs the pull-down operation, and therefore, thepotential of the reserved line 362 is down to 2.5 V whereas when thesync apparatus 200 is not the apparatus of the specific type, thereserved line 362 is opened and the potential thereof is up to 5 V.Accordingly, assuming that the reference potential of the signal line115 is set to 3.75 V, the type of the sync apparatus 200 is identifiedby the source apparatus 100 in accordance with an output of a signalline 117.

Similarly, when the source apparatus 100 is the apparatus of thespecific type, the resistor 111 performs the pull-up operation, andtherefore, the potential of the reserved line 362 is up to 2.5 V whereaswhen the source apparatus 100 is not the apparatus of the specific type,the potential of the reserved line 362 is down to 0 V. Accordingly,assuming that the reference potential of the signal line 214 is set to1.25 V, the type of the source apparatus 100 is identified by the syncapparatus 200 in accordance with an output of a signal line 217.

These signals used to detect the types of the apparatuses aretransmitted with DC bias potentials, and do not affect Ethernet(registered trademark) signals transmitted as AC signals.

FIG. 6 show diagrams illustrating examples of configurations of theplug-connection detection circuit 120 and the plug-connectiontransmission circuit 220 according to the embodiment of the presentinvention.

As shown in (a) FIG. 6, the plug-connection transmission circuit 220includes a choke coil 221 and resistors 222 and 223. The choke coil 221and the resistors 222 and 223 are used to bias the HPD line 363 toapproximately 4 V, for example.

Furthermore, as shown in (b) of FIG. 6, the plug-connection detectioncircuit 120 includes resistors 121 and 122, a capacitor 123, and acomparator 126. The resistor 121 is used to pull down the HPD line 363to the ground potential. The resistor 122 and the capacitor 123constitute a low-pass filter. An output of the low-pass filter issupplied to a signal line 124. The comparator 126 compares a DCpotential supplied from the low-pass filter to the signal line 124 witha reference potential applied to a signal line 125.

Here, it is assumed that a reference potential of 1.4 V is applied tothe signal line 125. When the source apparatus 100 is not connected tothe HPD line 363, the input potential is pulled down by the resistor121, and accordingly, the potential of the signal line 124 becomes lowerthan the reference potential of the signal line 125. On the other hand,when the source apparatus 100 is connected to the HPD line 363, theinput potential is biased to 4 V, and accordingly, the potential of thesignal line 124 becomes higher than the reference potential of thesignal line 125. Consequently, in accordance with an output from asignal line 127, the source apparatus 100 detects whether the syncapparatus 200 is connected.

These signals used for plug-connection detection are transmitted with DCbias potentials, and do not affect Ethernet (registered trademark)signals transmitted as AC signals.

Next, an example of a system configuration when an HDMI expandedapparatus is connected through the interface described above will bedescribed.

FIG. 7 is a diagram illustrating an example of a configuration of areproducing apparatus 710 according to the embodiment of the presentinvention. In this example of the system configuration, the reproducingapparatus 710 and a television receiver apparatus 720 are connected toeach other through the interface described above, and the reproducingapparatus 710 functions as a source apparatus and the televisionreceiver apparatus 720 functions as a sync apparatus. A signal line 701corresponds to the TMDS channels 310 to 330, a signal line 703corresponds to the display data channel 350, and a signal line 708corresponds to the reserved line 362 and the HPD line 363. Furthermore,a speaker 750 is connected to the reproducing apparatus 710 through ananalog signal line 709.

The reproducing apparatus 710 includes a player unit 730 whichreproduces video signals and audio signals recorded in a recordingmedium and an amplifier unit 740 which amplifies the audio signals. Theplayer unit 730 includes a recording-medium access unit 711, an inputselection unit 712, a transport-signal processor 713, a video-signaldecoding unit 714, and an audio-signal decoding unit 715. The amplifierunit 740 includes a delay-information obtaining unit 716 and anaudio-signal delaying unit 717.

The recording-medium access unit 711 reads signals including the videosignals and the audio signals from the recording medium. Here, it isassumed that a Blu-ray Disc ((registered trademark): BD) is employed asthe recording medium. In the Blu-ray Disc, signals (transport signals)complying with a transport stream (TS) method of MPEG (Moving PictureExpert Group)-2 are recorded, and the recording-medium access unit 711reads the transport signals and supplies them to the input selectionunit 712.

The input selection unit 712 selects a transport signal supplied fromthe television receiver apparatus 720 through the signal line 708 or atransport signal supplied from the recording-medium access unit 711, andsupplies the selected signal to the transport-signal processor 713.

The transport-signal processor 713 separates an encoded video signal andan encoded audio signal from the transport signal supplied from theinput selection unit 712. In the transport stream method of MPEG-2, avideo signal and an audio signal are encoded and transmitted as a TSpacket. That is, the transport-signal processor 713 generates an encodedelementary stream (ES) of the video signal and an encoded elementarystream of the audio signal from the TS packet.

The video-signal decoding unit 714 decodes the encoded video signalobtained through the separation operation of the transport-signalprocessor 713. The video signal decoded by the video-signal decodingunit 714 is supplied through the signal line 701 to the televisionreceiver apparatus 720.

The audio-signal decoding unit 715 decodes the encoded audio signalobtained through the separation operation of the transport-signalprocessor 713. The audio signal decoded by the audio-signal decodingunit 715 is supplied to the audio-signal delaying unit 717.

The delay-information obtaining unit 716 obtains a period of time (videoprocessing time) required for processing the video signal performed bythe television receiver apparatus 720 as delay information from thetelevision receiver apparatus 720 through the signal line 703. In theHDMI standard, a period of time required for processing the video signaland the audio signal performed is stored in the sync apparatus as partof E-EDID (Enhanced Extended Display Identification Data) configuration,and is supplied to the source apparatus through the display data channel(DDC). Note that, as another embodiment, the video processing time maybe obtained through transmission paths (the reserved line 362 and theHPD line 363) for Ethernet (registered trademark) signals.

The audio-signal delaying unit 717 delays the audio signal supplied fromthe audio-signal decoding unit 715 in accordance with the delayinformation (video processing time) obtained by the delay-informationobtaining unit 716. The delayed audio signal is amplified so as to be ananalog signal and output to the speaker 750 through the analog signalline 709.

The speaker 750 outputs the audio signal supplied from the audio-signaldelaying unit 717 as sound.

FIG. 8 is a diagram illustrating an example of a configuration of thetelevision receiver apparatus 720 according to the embodiment of thepresent invention. The connection relationship between the reproducingapparatus 710 and the television receiver apparatus 720 is the same asthat shown in the example of FIG. 7. Note that a signal line 704corresponding to the CEC line 361 is added. The television receiverapparatus 720 includes a delay-information storage unit 721, aconnection-apparatus-information management unit 722, a tuner 723, atransport-signal switching unit 724, a transport-signal processor 725, avideo-signal decoding unit 726, a display controller 727, and a displayunit 728.

The delay-information storage unit 721 stores a period of time requiredfor processing a video signal and an audio signal by the televisionreceiver apparatus 720 as one of characteristic information items of thetelevision receiver apparatus 720. The delay-information storage unit721 is realized by an EEPROM (Electronically Erasable and ProgrammableRead Only Memory). In the HDMI standard, the period of time required forprocessing a video signal and an audio signal is stored in the syncapparatus as part of the E-EDID configuration as described above, and issupplied from the sync apparatus through the display data channel (DDC)to the source apparatus. Note that, as another embodiment, the videoprocessing time may be transmitted through the transmission paths (thereserved line 362 and the HPD line 363) for Ethernet (registeredtrademark) signals.

The connection-apparatus-information management unit 722 managesinformation on various apparatuses which are directly or indirectlyconnected to the television receiver apparatus 720 and which areincluded in the AV system. The information on various apparatuses may beinformation on whether a decoder used to decode a specific encodedsignal is included, for example. In this example, theconnection-apparatus-information management unit 722 is connected to thereproducing apparatus 710 through the signal line 704, and obtainsinformation on the reproducing apparatus 710. In the HDMI standard,presences of other apparatuses are detected through the CEC line 361,and managements of the apparatuses are performed.

The tuner 723 receives a broadcast signal so as to select a channel. Ina case of digital broadcasting, a signal in accordance with thetransport stream (TS) method of MPEG-2 is generally obtained as thebroadcast signal.

The transport-signal switching unit 724 outputs a transport signalobtained by the tuner 723 to the transport-signal processor 725 or thereproducing apparatus 710 by selecting one of the transport-signalprocessor 725 and the reproducing apparatus 710. In this selection, thetransport-signal switching unit 724 selects one of them in accordancewith the information managed in the connection-apparatus-informationmanagement unit 722. For example, if a decoder used to decode thebroadcast signal included in another apparatus is available, decodingprocessing may be requested to the apparatus. Furthermore, the selectionmay be automatically performed in accordance with the informationmanaged in the connection-apparatus-information management unit 722, andalternatively, one of the apparatuses may perform the decodingprocessing in accordance with a user's instruction.

The transport-signal processor 725 separates an encoded video signal andan encoded audio signal from the transport signal output from thetransport-signal switching unit 724. Operation of the transport-signalprocessor 725 is the same as that of the transport-signal processor 713.

The video-signal decoding unit 726 decodes the encoded video signalobtained by the separation operation of the transport-signal processor725. Operation of the video-signal decoding unit 726 is the same as thatof the video-signal decoding unit 714.

The display controller 727 selects the video signal decoded by thevideo-signal decoding unit 726 or the video signal decoded by thereproducing apparatus 710, and outputs the selected video signal to thedisplay unit 728 for display. In this selection, the display controller727 determines a video signal to be selected in accordance with theinformation managed in the connection-apparatus-information managementunit 722. For example, if a decoder used to decode the broadcast signalincluded in another apparatus is available, a video signal decoded bythe apparatus may be selected. Furthermore, the selection may beautomatically performed in accordance with the information managed inthe connection-apparatus-information management unit 722, andalternatively, a video signal decoded by one of the apparatuses may beselected in accordance with a user's instruction.

The display unit 728 displays the video signal output from the displaycontroller 727, and is realized by an LCD (Liquid Crystal Display), forexample.

FIG. 9 is a diagram illustrating an example of a data configurationstored in the delay information storage unit 721 according to theembodiment of the present invention. This data configuration is based onVSDB (Vendor-Specific Data Block) complying with the HDMI standard, andincludes a vendor tag code, a block length, a licensor identifier, aphysical address, expansion information, a video delay amount, an audiodelay amount, an interlace video delay amount, and an interlace audiodelay amount.

The vendor tag code corresponds to a region of three bits which stores anumber representing this data configuration, and is “3”. The blocklength corresponds to a region of five bits which stores the number ofbytes (N) of this data configuration. The licensor identifiercorresponds to a region of three bytes which stores an identifierassigned to the organization of the HDMI standard. The physical addresscorresponds to a region of two bytes which stores a physical address ofthe source apparatus which is used by the CEC line 361. The expansioninformation corresponds to a region of three bytes which storesinformation on support of an expansion function. Note that the expansioninformation includes effective bits of the following delay amounts.

The video delay amount corresponds to a region of one byte which storesa period of time (video processing time) from when the televisionreceiver apparatus 720 receives a video signal to when a video image isactually displayed provided that the video signal is in a progressiveform. The audio delay amount corresponds to a region of one byte whichstores a period of time from when the television receiver apparatus 720receives an audio signal corresponding to the video signal to when soundis actually output provided that the video signal is in a progressiveform. The interlace video delay amount corresponds to a region of onebyte which stores a period of time from when the television receiverapparatus 720 receives a video signal to when a video image is actuallydisplayed provided that the video image is in an interlace form. Theinterlace audio delay amount corresponds to a region of one byte whichstores a period of time from when the television receiver apparatus 720receives an audio signal corresponding to the video signal to when soundis actually output when the video signal is in an interlace form.

Note that the interlace audio delay amount is followed by a reservedregion, and a region of the data configuration corresponds to a blocklength (N bytes).

The delay-information obtaining unit 716 of reproducing apparatus 710serving as the source apparatus obtains the video delay amount or theinterlace video delay amount in the data configuration as delayinformation. That is, when the video signal is in a progressive form,the video delay amount corresponds to the delay information whereas whenthe video signal is in an interlace form, the interlace video delayamount corresponds to the delay information. The audio-signal delayingunit 717 delays an audio signal supplied from the audio-signal decodingunit 715 by a period of time obtained by subtracting a period of time(audio processing time) in which an audio signal is processed in thereproducing apparatus 710 from the obtained delay information. By this,a video image displayed in the television receiver apparatus 720 andsound output from the speaker 750 are synchronized with each other, andlip sync is ensured.

FIG. 10 is a diagram illustrating an example of a procedure ofprocessing of the reproducing apparatus 710 according to the embodimentof the present invention. In FIG. 10, a procedure of processing of theplayer unit 730 is shown on the right side, and a procedure ofprocessing of the amplifier unit 740 is shown on the left side. Here, itis assumed that a transport signal output from the television receiverapparatus 720 is selected by the input selection unit 712.

When receiving a transport signal supplied from the television receiverapparatus 720 through the input selection unit 712 (in step S911), thetransport-signal processor 713 separates a video signal and an audiosignal from the transport signal (in step S912). The video-signaldecoding unit 714 decodes the separated video signal and supplies it tothe television receiver apparatus 720 (in step S913). Furthermore, theaudio-signal decoding unit 715 decodes the separated audio signal andsupplies it to the audio-signal delaying unit 717 (in step S914).

The delay-information obtaining unit 716 receives the delay informationfrom the television receiver apparatus 720 through the signal line 703(DDC) (in step S921). The audio-signal delaying unit 717 calculates adelay amount by subtracting the audio processing time of the reproducingapparatus 710 from the obtained delay information (in step S923). Then,the audio-signal delaying unit 717 receives the supplied audio signalfrom the audio-signal decoding unit 715 (in step S924), delays the audiosignal in accordance with the delay amount (in step S925), and outputthe audio signal to the speaker 750 (in step S926).

FIG. 11 is a diagram illustrating an example of a procedure ofprocessing of the television receiver apparatus 720 according to theembodiment of the present invention.

When the tuner 723 selects a broadcast signal including the transportsignal (in step S931), the transport-signal switching unit 724determines whether the transport signal is to be decoded in thetelevision receiver apparatus 720 (in step S932). At this time, thetransport-signal switching unit 724 may make the determination inaccordance with the information managed in theconnection-apparatus-information management unit 722 or in accordancewith a user's instruction.

When it is determined that the transport signal is to be decoded in thetelevision receiver apparatus 720 (in step S932), the transport-signalprocessor 725 separates a video signal from the transport signal, andthe separated video signal is decoded by the video-signal decoding unit726 (in step S933).

On the other hand, when it is determined that a decoding request issupplied to the reproducing apparatus 710 (in step S932), thetransport-signal switching unit 724 outputs the transport signalincluded in the broadcast signal to the reproducing apparatus 710through the signal line 708 (in step S936). Before this operation, thedelay information stored in the delay-information storage unit 721 issupplied to the reproducing apparatus 710 through the signal line 703 inadvance (in step S934). The display controller 727 receives the videosignal decoded by the reproducing apparatus 710 (in step S937).

The display controller 727 selects the video signal decoded by thevideo-signal decoding unit 726 or the video signal decoded by thereproducing apparatus 710, and displays the selected video signal in thedisplay unit 728 (in step S938).

Note that, in the example, it is assumed that the display data channel350 complying with the HDMI standard is employed when the delayinformation is transmitted. However, the delay information may betransmitted as an Ethernet (registered trademark) signal using thereserved line 362 and the HPD line 363.

Next, an example of another system configuration when an HDMI expandedapparatus is connected through the interface described above will bedescribed.

FIG. 12 is a diagram illustrating an example of another systemconfiguration according to the embodiment of the present invention. Inthis configuration example, a PVR (Personal Video Recorder: hard diskdrive recorder) 810, an STB (Set Top Box) 820, a D-VHS (Data Video HomeSystem) reproducing apparatus 830, an AV amplifier 840, a DVD (DigitalVersatile Disk) reproducing apparatus 860, and a television receiverapparatus 870 are connected through the interface described above. InFIG. 12, sources of arrows denote source apparatuses, and destinationsof the arrows denote sync apparatuses. Furthermore, a speaker 850 isconnected to the AV amplifier 840 through an analog signal line.

When a normal HDMI cable is used, a video signal and an audio signal aresupplied from a source apparatus to a sync apparatus, and therefore, inthis connection example, it is possible to output a signal reproduced bythe DVD reproducing apparatus 860 from the television receiver apparatus870, but it is not possible to output an audio signal from the speaker850. On the other hand, since the interface described with reference toFIGS. 3 to 6 may perform bi-directional transmission of signals, it ispossible to transmit the audio signal from the television receiverapparatus 870 to the AV amplifier 840.

FIG. 13 is a diagram illustrating a path of an audio signal in theexample of the other system configuration according to the embodiment ofthe present invention.

In this example, it is assumed that a decoding request is transmitted tothe STB 820 and sound is output from the speaker 850. An encoded videosignal and an encoded audio signal read from a DVD by the DVDreproducing apparatus 860 are transmitted as Ethernet (registeredtrademark) signals through the reserved line 362 and the HPD line 363 tothe STB 820.

The STB 820 which has a configuration the same as that of the playerunit 730 described with reference to FIG. 7 decodes the encoded videosignal and the encoded audio signal. The video signal and the audiosignal decoded by the STB 820 are supplied to the AV amplifier 840through the TMDS channels 310 to 330.

The AV amplifier 840 transmits the video signal to the televisionreceiver apparatus 870 through the TMDS channels 310 to 330, delays theaudio signal using a configuration the same as that of the amplifierunit 740 described with reference to FIG. 7, and outputs the delayedaudio signal to the speaker 850.

As described above, according to the embodiment of the presentinvention, in the system using the interface based on thesingle-directional transmission such as the interface complying with theHDMI standard, flexible reproduction is performed irrespective of aconnection state of apparatuses. Furthermore, at this time,synchronization (lip sync) between a reproduced video image andreproduced sound is ensured.

Moreover, according to the embodiment of the present invention, since arequest for decoding processing may be supplied to another apparatus,flexible reproduction is performed without restrictions of the number ofdecoders in an apparatus and a version of the apparatus. For example,when the television receiver apparatus 870 includes a single decoder, asingle broadcast signal is decoded by the apparatus, and a request fordecoding of another broadcast signal is supplied to another apparatus,and accordingly, display of a plurality of broadcast programs may beperformed in display screens 610 and 620 of a screen 600 shown in FIG.14. That is, assuming that the number of the video decoding units andthe audio decoding units is each set to n (n is an integer number equalto or larger than 0), n or more video images or sounds may be output.

Next, a modification of the embodiment of the present invention will bedescribed.

FIG. 15 show diagrams illustrating examples of modifications of internalconfigurations of the source apparatus 100 and the sync apparatus 200.Here, similarly to FIG. 3, configurations regarding the reserved line362 and the HPD line 363 are shown. When compared with the configurationexamples of FIG. 3, an SPDIF (Sony Philips Digital InterFace) receptioncircuit 170 is added to the source apparatus 100, and an SPDIFtransmission circuit 270 is added to the sync apparatus 200.

The SPDIF reception circuit 170 and the SPDIF transmission circuit 270perform single-directional communication complying with an SPDIFstandard. Note that, the SPDIF standard is an interface standard used totransmit digital audio signals in real time, and is standardized as “IEC60958” in the IEC (International Electrotechnical Commission). An SPDIFsignal transmitted in accordance with the SPDIF standard includes aclock component for bi-phase mark modulation. Note that the SPDIFreception circuit 170 and the SPDIF transmission circuit 270 arerealized by the related art.

FIG. 16 shows diagrams illustrating examples of modifications ofconfigurations of the source-side transmission/reception circuit 140 andthe sync-side transmission/reception circuit 250 according to theembodiment of the present invention.

As shown in (a) of FIG. 16, the sync-side transmission/reception circuit250 includes the amplifiers 510, 520, 530, and 550, the inverter 541,the adder 542, and adders 571, and 572. That is when compared with theconfiguration example in (a) of FIG. 4, this configuration additionallyincludes the adders 571 and 572.

The adder 571 is a circuit which adds a signal supplied from the SPDIFtransmission circuit 270 through a signal line 561 and a positive outputfrom the amplifier 520 to each other. The adder 572 and the adder 571are circuits which add signals supplied from the SPDIF transmissioncircuit 270 through a signal line 561 and a negative output from theamplifier 520 to each other.

That is, although Ethernet (registered trademark) signals output fromthe amplifier 550 are differential signals, SPDIF signals superimposedin the adders 571 and 572 are in-phase signals. Accordingly, both theEthernet (registered trademark) signals and the SPDIF signals may betransmitted in the same pair of signal lines (the reserved line 362 andthe HPD line 363).

As shown in (b) of FIG. 16, the source-side transmission/receptioncircuit 140 includes the amplifiers 410, 420, 430, and 450, the inverter441, and the adder 442, and an adder 460. That is, when compared withthe configuration example in (b) of FIG. 4, this configurationadditionally includes adder 460.

The adder 460 is a circuit which adds a positive signal and a negativesignal output from the amplifier 420 to each other. That is, amongsignals transmitted through the reserved line 362 and the HPD line 363,differential signals are extracted by the amplifier 430 as Ethernet(registered trademark) signals, and in-phase signals are extracted bythe adder 460 as SPDIF signals. An output from the adder 460 is suppliedto the SPDIF reception circuit 170.

FIG. 17 is a diagram illustrating an example of a modification of thereproducing apparatus 710 according to the embodiment of the presentinvention. In this modification, a signal line 707 used to transit SPDIFsignals and a signal line 702 used to transmit audio signals are addedto the configuration example shown in FIG. 7. Note that, as describedabove, an SPDIF signal may be superimposed with an Ethernet (registeredtrademark) signal so as to be transmitted through the same pair ofsignal lines (the reserved line 362 and the HPD line 363), andtherefore, the transmission is realized without physically adding acable. Furthermore, since the signal line 702 and the signal line 701are realized by the TMDS channels 310 to 330, the signal line 702 isrealized without physically adding a cable.

In this modification, instead of the delay-information obtaining unit716 shown in FIG. 7, a delay-time measurement unit 718 is provided.Then, an audio signal output from the audio-signal decoding unit 715 issupplied to the delay-time measurement unit 718, and is also supplied tothe television receiver apparatus 720 through the signal line 702. Thedelay-time measurement unit 718 measures a difference (displacement), asvideo processing time, between an audio signal returned from thetelevision receiver apparatus 720 through the signal line 707 and anaudio signal output from the audio-signal decoding unit 715.

In this case, the delay-time measurement unit 718 may obtain the videoprocessing time in accordance with the cross-correlation between theaudio signal returned from the television receiver apparatus 720 and theaudio signal output from the audio-signal decoding unit 715.Furthermore, a signal for measurement having a specific pattern istransmitted, and a response to the signal for measurement is transmittedfrom the television receiver apparatus 720 to the delay-time measurementunit 718 so that a response time thereof is obtained as the videoprocessing time.

FIG. 18 is a diagram illustrating an example of a modification of aconfiguration of the television receiver apparatus 720 according to theembodiment of the present invention. The connection relationship betweenthe reproducing apparatus 710 and the television receiver apparatus 720is the same as that shown in FIG. 17. Note that the signal line 704corresponding to the CEC line 361 is added.

In this modification, instead of the delay-information storage unit 721shown in FIG. 8, an audio-signal returning unit 729 is provided. Theaudio-signal returning unit 729 returns, at a timing when a video signaldecoded by the reproducing apparatus 710 is displayed in the displayunit 728, an audio signal temporally corresponding to the video signalto the reproducing apparatus 710 through the signal line 707. The timingwhen a video signal is displayed in the display unit 728 is transmittedfrom the display controller 727 to the audio-signal returning unit 729.

FIG. 19 is a diagram illustrating an example of a modification of theprocedure of the processing of the reproducing apparatus 710 accordingto the embodiment of the present invention. In FIG. 19, a procedure ofprocessing of the player unit 730 is shown on the right side, and aprocedure of processing of the amplifier unit 740 is shown on the leftside. Accordingly, the processing procedure on the right side of FIG. 19is the same as the processing procedure on the right side of FIG. 10.Note that the processing procedure on the right side of FIG. 19 isdifferent from the processing procedure on the right side of FIG. 10 inthat an audio signal decoded in step S914 is transmitted to thetelevision receiver apparatus 720.

The delay-time measurement unit 718 receives an audio signal returnedfrom the television receiver apparatus 720 through the signal line 707(in step S941), and measures a temporal difference between the returnedaudio signal and an audio signal output from the audio-signal decodingunit 715 as a delay time (video processing time) (in step S942). Theaudio-signal delaying unit 717 calculates a delay amount by subtractingthe audio processing time in the reproducing apparatus 710 from theobtained delay time (in step S943). Then, the audio-signal delaying unit717 receives the audio signal supplied from the audio-signal decodingunit 715 (in step S944), delays the audio signal in accordance with thedelay amount (in step S945), and outputs the audio signal to the speaker750 (in step S946).

FIG. 20 is a diagram illustrating an example of a modification of theprocedure of the processing of the television receiver apparatus 720according to the embodiment of the present invention. The configurationof FIG. 20 is made assuming that the configuration example shown in FIG.18 is employed.

When the tuner 723 selects a broadcast signal including a transportsignal (in step S951), the transport-signal switching unit 724determines whether the transport signal is to be decoded in thetelevision receiver apparatus 720 (in step S952). When it is determinedthat the transport signal is to be decoded in the television receiverapparatus 720, the transport-signal processor 725 separates a videosignal from the transport signal, and the separated video signal isdecoded by the video-signal decoding unit 726 (in step S953). Theseoperations are the same as those of FIG. 11.

On the other hand, when it is determined that a decoding request is tobe transmitted to the reproducing apparatus 710 (in step S952), thetransport-signal switching unit 724 outputs the transport signalincluded in the broadcast signal to the reproducing apparatus 710through the signal line 708 (in step S956). Before this operation, theaudio-signal returning unit 729 receives an audio signal from thereproducing apparatus 710 through the signal line 702 (in step S954),and returns, at a timing when a video signal decoded by the reproducingapparatus 710 is displayed in the display unit 728, an audio signaltemporally corresponding to the video signal to the reproducingapparatus 710 through the signal line 707 (in step S955). The displaycontroller 727 receives the video signal decoded by the reproducingapparatus 710 (in step S957).

According to this modification, synchronization of a reproduced videoimage and reproduced sound is ensured by actually measuring a delaytime, without storing delay information in the television receiverapparatus 720.

Note that the embodiment of the present invention is merely an examplewhich realizes the present invention, and the elements of the embodimenthave correspondence relationships with respective specific elements ofthe invention in the claims as described below. However, the presentinvention is not limited to these, and various modifications may be madewithout departing from the scope of the invention.

Specifically, a stream generation apparatus and a video-image outputtingapparatus corresponds to the television receiver apparatus 720, forexample. Furthermore, separation means corresponds to thetransport-signal processor 713, for example. Moreover, video-signaldecoding means corresponds to the video-signal decoding unit 714, forexample. In addition, audio-signal decoding means corresponds to theaudio-signal decoding unit 715, for example. Furthermore, audio-signalprocessing means corresponds to the amplifier unit 740, for example.

Furthermore, first reception means corresponds to the amplifier 430, forexample. Moreover, second reception means corresponds to the adder 460,for example.

Furthermore, stream-signal generation means corresponds to the tuner723, for example. Moreover, connection-information management meanscorresponds to the connection-apparatus-information management unit 722,for example. In addition, stream-signal switching means corresponds tothe transport-signal switching unit 724, for example. Furthermore,display means corresponds to the display unit 728, for example.Moreover, display control means corresponds to the display controller727, for example. In addition, video-processing-time supplying meanscorresponds to the delay-information storage unit 721, for example.

Furthermore, separation means corresponds to the transport-signalprocessor 725, for example. Moreover, video-signal decoding meanscorresponds to the video-signal decoding unit 726, for example.

Furthermore, video-signal decoding means corresponds to the video-signaldecoding unit 726, for example.

Moreover, audio-signal returning means corresponds to the audio-signalreturning unit 729, for example.

Furthermore, first transmission means corresponds to the amplifier 520,for example. Moreover, second transmission means corresponds to theadders 571 and 572, for example.

Furthermore, a reception step corresponds to step S911, for example.Moreover, a separation step corresponds to step S912, for example. Inaddition, a video-signal decoding step corresponds to step S913, forexample. Furthermore, an audio-signal decoding step corresponds to stepS914, for example. Moreover a video-signal-processing-time obtainingstep corresponds to step S921, for example. In addition, an audio-signaldelaying step corresponds to step S923 to step S926, for example.

Furthermore, connection-information management means corresponds to theconnection-apparatus-information management unit 722, for example.Moreover, display means corresponds to the display unit 728, forexample. In addition, display control means corresponds to the displaycontroller 727, for example. Furthermore, a stream-signal generationstep corresponds to step S931, for example. Moreover, a determinationstep corresponds to step S932, for example. In addition, avideo-processing-time supplying step corresponds to step S934, forexample. Furthermore, a stream-signal switching step corresponds to stepS936, for example. Moreover, a display control step corresponds to stepS937 and step S938, for example.

Note that the processing steps described in the embodiment of thepresent invention may be perceived as a method including a series of thesteps, or may be perceived as a program which makes a computer executethe series of the steps or a recording medium storing the program.

1. A reproducing apparatus, comprising: separation means for receiving astream signal including an encoded video signal and an encoded audiosignal from a stream generation apparatus and separating the encodedvideo signal and the encoded audio signal from the stream signal;video-signal decoding means for decoding the encoded video signal andoutputting the decoded video signal to a video-image outputtingapparatus; audio-signal decoding means for decoding the encoded audiosignal to generate a decoded audio signal and outputting the decodedaudio signal to the video-image outputting apparatus; and audio-signalprocessing means for measuring a temporal difference between an audiosignal returned from the video-image outputting apparatus and the audiosignal decoded by the audio-signal decoding means as video processingtime, delaying the audio signal in accordance with the video processingtime, and thereafter supplying the delayed audio signal to an audiooutputting apparatus.
 2. The reproducing apparatus according to claim 1,wherein the audio-signal processing means obtains the video processingtime through a control signal line connected between the audio-signalprocessing means and the video-image outputting apparatus.
 3. Thereproducing apparatus according to claim 2, wherein the control signalline corresponds to a display data channel (DDC) included in an HDMIcable.
 4. The reproducing apparatus according to claim 1, wherein theseparation means receives the stream signal through a data signal lineconnected between the separation means and the stream generationapparatus.
 5. The reproducing apparatus according to claim 4, whereinthe stream generation apparatus is included in the video-imageoutputting apparatus, and the audio-signal processing means obtains thevideo processing time through the data signal line.
 6. The reproducingapparatus according to claim 4, wherein the data signal line correspondsto a reserved line and a hot-plug detection line included in an HDMIcable.
 7. A reproducing apparatus, comprising: separation means forreceiving a stream signal including an encoded video signal and anencoded audio signal from a stream generation apparatus and separatingthe encoded video signal and the encoded audio signal from the streamsignal; video-signal decoding means for decoding the encoded videosignal and outputting the decoded video signal to a video-imageoutputting apparatus; audio-signal decoding means for decoding theencoded audio signal to generate a decoded audio signal and outputtingthe decoded audio signal to the video-image outputting apparatus;audio-signal processing means for measuring a temporal differencebetween an audio signal returned from the video-image outputtingapparatus and the audio signal decoded by the audio-signal decodingmeans as video processing time, delaying the audio signal in accordancewith the video processing time, and thereafter supplying the delayedaudio signal to an audio outputting apparatus; first reception means forextracting the stream signal from a difference signal received through adata signal line connected between the first reception means and thevideo-image outputting apparatus; and second reception means forextracting the returned audio signal from an in-phase signal receivedthrough the data signal line.
 8. The reproducing apparatus according toclaim 7, wherein the data signal line corresponds to a reserved line anda hot-plug detection line included in an HDMI cable.
 9. The reproducingapparatus according to claim 7, wherein the audio-signal processingmeans obtains the video processing time through a control signal lineconnected between the audio-signal processing means and the video-imageoutputting apparatus.
 10. The reproducing apparatus according to claim9, wherein the control signal line corresponds to a display data channel(DDC) included in an HDMI cable.
 11. The reproducing apparatus accordingto claim 7, wherein the separation means receives the stream signalthrough a data signal line connected between the separation means andthe stream generation apparatus.
 12. The reproducing apparatus accordingto claim 11, wherein the stream generation apparatus is included in thevideo-image outputting apparatus, and the audio-signal processing meansobtains the video processing time through the data signal line.
 13. Areproducing method, comprising: a reception step of receiving a streamsignal including an encoded video signal and an encoded audio signalfrom a stream generation apparatus; a separation step of separating theencoded video signal and the encoded audio signal from the streamsignal; a video-signal decoding step of decoding the encoded videosignal and outputting a decoded video signal to a video-image outputtingapparatus; an audio-signal decoding step of decoding the encoded audiosignal so that a decoded audio signal is generated and outputting thedecoded audio signal to the video-image outputting apparatus; avideo-processing-time obtaining step of measuring a temporal differencebetween an audio signal returned from the video-image outputtingapparatus and the audio signal decoded in the audio-signal decoding stepas video processing time; and an audio-signal delaying step of delayingthe audio signal in accordance with the video processing time, andthereafter supplying the delayed audio signal to an audio outputtingapparatus.
 14. A reproducing apparatus, comprising: a separation unitthat receives a stream signal including an encoded video signal and anencoded audio signal from a stream generation apparatus and separatesthe encoded video signal and the encoded audio signal from the streamsignal; a video-signal decoding unit that decodes the encoded videosignal and outputs the decoded video signal to a video-image outputtingapparatus; audio-signal decoding unit that decodes the encoded audiosignal to generate a decoded audio signal and outputs the decoded audiosignal to the video-image outputting apparatus; and audio-signalprocessing unit that measures a temporal difference between an audiosignal returned from the video-image outputting apparatus and the audiosignal decoded by the audio-signal decoding unit as video processingtime, delays the audio signal in accordance with the video processingtime, and thereafter supplies the delayed audio signal to an audiooutputting apparatus.
 15. The reproducing apparatus according to claim14, wherein the audio-signal processing unit obtains the videoprocessing time through a control signal line connected between theaudio-signal processing unit and the video-image outputting apparatus.16. The reproducing apparatus according to claim 15, wherein the controlsignal line corresponds to a display data channel (DDC) included in anHDMI cable.
 17. The reproducing apparatus according to claim 14, whereinthe separation unit receives the stream signal through a data signalline connected between the separation unit and the stream generationapparatus.
 18. The reproducing apparatus according to claim 17, whereinthe stream generation apparatus is included in the video-imageoutputting apparatus, and the audio-signal processing unit obtains thevideo processing time through the data signal line.
 19. The reproducingapparatus according to claim 17, wherein the data signal linecorresponds to a reserved line and a hot-plug detection line included inan HDMI cable.
 20. A reproducing apparatus, comprising: a separationunit that receives a stream signal including an encoded video signal andan encoded audio signal from a stream generation apparatus and separatesthe encoded video signal and the encoded audio signal from the streamsignal; a video-signal decoding unit that decodes the encoded videosignal and outputs the decoded video signal to a video-image outputtingapparatus; a audio-signal decoding unit that decodes the encoded audiosignal to generate a decoded audio signal and outputs the decoded audiosignal to the video-image outputting apparatus; a audio-signalprocessing unit that measures a temporal difference between an audiosignal returned from the video-image outputting apparatus and the audiosignal decoded by the audio-signal decoding unit as video processingtime, delays the audio signal in accordance with the video processingtime, and thereafter supplies the delayed audio signal to an audiooutputting apparatus; a first reception unit that extracts the streamsignal from a difference signal received through a data signal lineconnected between the first reception unit and the video-imageoutputting apparatus; and a second reception unit that extracts thereturned audio signal from an in-phase signal received through the datasignal line.
 21. The reproducing apparatus according to claim 20,wherein the data signal line corresponds to a reserved line and ahot-plug detection line included in an HDMI cable.
 22. The reproducingapparatus according to claim 20, wherein the audio-signal processingunit obtains the video processing time through a control signal lineconnected between the audio-signal processing unit and the video-imageoutputting apparatus.
 23. The reproducing apparatus according to claim22, wherein the control signal line corresponds to a display datachannel (DDC) included in an HDMI cable.
 24. The reproducing apparatusaccording to claim 20, wherein the separation unit receives the streamsignal through a data signal line connected between the separation unitand the stream generation apparatus.
 25. The reproducing apparatusaccording to claim 24, wherein the stream generation apparatus isincluded in the video-image outputting apparatus, and the audio-signalprocessing unit obtains the video processing time through the datasignal line.